powerpc/tau: Disable TAU between measurements
Enabling CONFIG_TAU_INT causes random crashes:
Unrecoverable exception 1700 at
c0009414 (msr=1000)
Oops: Unrecoverable exception, sig: 6 [#1]
BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted
5.7.0-pmac-00043-gd5f545e1a8593 #5
NIP:
c0009414 LR:
c0009414 CTR:
c00116fc
REGS:
c0799eb8 TRAP: 1700 Not tainted (
5.7.0-pmac-00043-gd5f545e1a8593)
MSR:
00001000 <ME> CR:
22000228 XER:
00000100
GPR00:
00000000 c0799f70 c076e300 00800000 0291c0ac 00e00000 c076e300 00049032
GPR08:
00000001 c00116fc 00000000 dfbd3200 ffffffff 007f80a8 00000000 00000000
GPR16:
00000000 00000000 00000000 00000000 00000000 00000000 00000000 c075ce04
GPR24:
c075ce04 dfff8880 c07b0000 c075ce04 00080000 00000001 c079ef98 c079ef5c
NIP [
c0009414] arch_cpu_idle+0x24/0x6c
LR [
c0009414] arch_cpu_idle+0x24/0x6c
Call Trace:
[
c0799f70] [
00000001] 0x1 (unreliable)
[
c0799f80] [
c0060990] do_idle+0xd8/0x17c
[
c0799fa0] [
c0060ba4] cpu_startup_entry+0x20/0x28
[
c0799fb0] [
c072d220] start_kernel+0x434/0x44c
[
c0799ff0] [
00003860] 0x3860
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX
3d20c07b XXXXXXXX XXXXXXXX XXXXXXXX
7c0802a6
XXXXXXXX XXXXXXXX XXXXXXXX
4e800421 XXXXXXXX XXXXXXXX XXXXXXXX
7d2000a6
---[ end trace
3a0c9b5cb216db6b ]---
Resolve this problem by disabling each THRMn comparator when handling
the associated THRMn interrupt and by disabling the TAU entirely when
updating THRMn thresholds.
Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5a0ba3dc5612c7aac596727331284a3676c08472.1599260540.git.fthain@telegraphics.com.au